Yesterday, I planned to “re-start” downloading the latest software for all of the avionics which have updatable software modules so I could begin to configure my system with correct input/output formats. As I turned on the Master Switch, the Ray Ellen Trim Servo Indicators lit up but quickly shut down and a fuse blew. I replaced the fuse but the Aileron Trim Hat Switch did not activate the Aileron Trim Servo but the Elevator Trim worked; still no indicator lights for either trim servo. I started trouble shooting from the indicators all the way back through the stick controls and finally the control panel. After 5 ½ hours, I finally found a loose wire inside the Ray Ellen Aileron Servo. I repaired the fault and put a blob of RTV on the exterior of the servo so the wires would not wiggle/vibrate in flight. I’m not sure why the connection failed, but everything is working OK now. Tomorrow, I will once again attempt to configure all my computer-driven avionics so it all ‘talks’ together as an integrated system.